Yes, antihistamines can contribute to Candida.
I ve been noticing the phlem in my throat is probably from my chronic sinusitis. However I wonder if its the yeast.
Both of these are Candida symptoms. I’m really curious as to how you can say that wheat doesn’t bother you when you still have many symptoms. Also, since your Italian have you been tested for Celiacs? This disease is very common in Italian blood lines, and could be the reason for your leaky gut.